On the quantitative determination of hole-concentration in high-temperature cuprate superconductors

Abstract

We compared four hole-scales that have been used to determine the hole-concentration in high-temperature cuprate superconductors. We show that the hole-scale, [Formula: see text]-scale, based on the thermoelectric power [T. Honma et al., Phys. Rev. B 70, (2004) 214517.] is quantitatively consistent with spectroscopic probes for many different cuprate materials, while the other hole-scales, based on a well-known dome-shaped [Formula: see text]-curve [M. R. Presland et al., Physica C 176, 95 (1991)], the [Formula: see text]-axis lattice parameter [R. Liang et al., Phys. Rev. B 73, (2006) 180505(R).] and Hall coefficient [Y. Ando et al., Phys. Rev. B 61, (2000) 14956(R).], are not. We show that the quantitatively different hole-scales resulted in opposite conclusion of the same experimental observations. It can also lead to different interpretations of the electronic phase diagram when comparing different physical properties in different high-[Formula: see text] systems. We suggest that the [Formula: see text]-scale is the correct universal scale that works for all high-[Formula: see text] cuprates and it should be used for all quantitative doping dependence studies of cuprates.